Preparation Preheat oven to 350°F. Toast walnuts on a rimmed baking sheet, tossing once, until golden brown, 8–10 minutes. Let cool, then coarsely chop. Using a paring knife, remove cores from brussels sprouts through stem ends; discard. Peel off leaves all the way down to the very center. Heat 2 Tbsp. olive oil in a large skillet over medium-high. Add a quarter of the brussels sprout leaves and cook, tossing once or twice, until bright green and deeply charred in spots, about 4 minutes. Season with salt and pepper; transfer to a platter. Repeat process 3 more times with remaining brussels sprouts and olive oil. Finely grate lemon zest over brussels sprouts, then squeeze juice on top. Scatter walnuts over and drizzle with walnut oil. Finish with a few cranks of pepper. Do Ahead Brussels sprouts can be cored and leaves separated 3 days ahead. Wrap in damp paper towels and store in resealable plastic bags; chill.
Preparation Preheat oven to 350°F. Toast walnuts on a rimmed baking sheet, tossing once, until golden brown, 8–10 minutes. Let cool, then coarsely chop. Using a paring knife, remove cores from brussels sprouts through stem ends; discard. Peel off leaves all the way down to the very center. Heat 2 Tbsp. olive oil in a large skillet over medium-high. Add a quarter of the brussels sprout leaves and cook, tossing once or twice, until bright green and deeply charred in spots, about 4 minutes. Season with salt and pepper; transfer to a platter. Repeat process 3 more times with remaining brussels sprouts and olive oil. Finely grate lemon zest over brussels sprouts, then squeeze juice on top. Scatter walnuts over and drizzle with walnut oil. Finish with a few cranks of pepper. Do Ahead Brussels sprouts can be cored and leaves separated 3 days ahead. Wrap in damp paper towels and store in resealable plastic bags; chill.